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Biomedical subjects

C Bartolozzi

Publications and source records attributed to C Bartolozzi.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Usefulness and safety of pirenzepine in double-contrast study of upper gastrointestinal tract: comparison with scopolamine methylbromide.

To evaluate usefulness of pirenzepine, a selective M1 antimuscarinic drug, for diagnostic double-contrast study of the upper gastrointestinal tract, pirenzepine and scopolamine methylbromide (SMB) were compared in a single blind randomized trial. Seventy consecutive patients were enrolled in the study. Artifacts, bowel distention, painting of stomach and duodenal bulb, and global quality of the images were blindly evaluated by four independent observers by means of a numerical score (1-4). Under SMB slightly but significantly better results for stomach were scored (3.1 +/- .7 vs. 2.7 +/- 7, p < 0.01). No differences were found in the study of the duodenal bulb. Heart rate and rhythm during the study were recorded by electrocardiogram (ECG). SMB induced tachycardia in all patients (from 77 +/- 20 to 117 +/- 28 beats/min, p < 0.01) while pirenzepine did not (from 77 +/- 16 to 81 +/- 23, p = NS). After SMB, two patients exhibited faintness, and some patients complained of visual accommodation defects, dryness of the mouth, and dizziness. Thus, pirenzepine provides good results in double-contrast studies (equal to SMB), while presenting no adverse effects. It could be proposed as a first choice hypotonic agent in upper gastrointestinal examination.

Adult↗
PubMedDate not supplied

Liver and spleen enhancement after intravenous injection of carboxydextran magnetite: effect of dose, delay of imaging, and field strength in an ex vivo model.

It has been predicted that liver and spleen enhancement after administration of superparamagnetic contrast agents may be different, depending on the strength of the main magnetic field. With the use of an ex vivo model, we investigated at 0.3, 0.5, and 1.5 T the effects on liver and spleen signal intensity of 5, 15, and 45 mumol/kg body weight of dextran magnetite (SHU 555A) in 54 rats. Nine rats served as controls. At different time delays since injection, the animals were killed, and after perfusion with saline, the liver, brain, and spleen were fixed in formalin. The specimens were embedded in an agar gel matrix and imaged with inversion recovery T1-weighted, proton density spin echo, and T2*-weighted gradient recalled echo (GRE) sequences. At each magnetic field strength, peak liver and spleen signal loss increased with increasing dose of the contrast medium. Signal loss was significantly more conspicuous after a dose of 15 than 5 mumol/kg body weight, but not after a dose of 45 compared with 15 mumol/kg. No signal change was observed in the brain. GRE images showed higher enhancement than proton density-weighted spin echo and inversion recovery images but were noisier. The enhancement showed a plateau between 30 min and 24 hours. Only the signal decrease of the liver after a low dose of contrast medium on GRE images was significantly higher (p < 0.01) at 1.5 than at 0.5 and 0.3 T. Other differences in respect to the field strength were less significant (p < 0.05) or nonsignificant. Differences in the spleen enhancement were nonsignificant. SHU 555A at a dose of 15 mumol/kg is an efficient intracellular contrast agent for liver and spleen at low, mid, and high field strength. Proton density spin echo images are probably the sequence of choice to exploit SHU 555A contrast effects and a wide time window for imaging after its intravenous injection does exist.

Animals↗
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Multidetector CT and virtual endoscopy in the evaluation of the esophagus.

In this prospective study, we assessed the diagnostic capabilities of multidetector computed tomography (CT) in various esophageal pathologic conditions. Thirty-three patients underwent a multidetector CT study after esophageal distention by means of effervescent powder administered after induction of pharmacologic esophageal hypotonia. All acquired images were post-processed with two- and three-dimensional software tools. The CT data were compared with the results of conventional radiology (33), endoscopy (28), endoscopy ultrasonography (14), or surgery (14). Follow-up ranged between 4 and 15 months. Esophageal distention in the upper and middle thirds was classified as "good" in 32 of 33 cases (97%); in the lower third, esophageal distention was "good" in 21 of 33 cases (64%). Final diagnoses were leiomyoma (six cases), squamous cell carcinoma (six), adenocarcinoma (four), esophageal infiltration by thyroid cancer (two), benign polyposis (two), chronic esophagitis (five), post-sclerotherapy stenosis (one), no abnormalities (seven). When good distention was achieved, the thickness of unaffected esophageal wall was less than 3 mm (range, 1.5-2.4 mm; mean, 1.9 mm). Pathologic wall thickening was observed in 25 of 33 cases (76%), with values ranging between 3.6 and 36 mm (mean, 9.6 mm). Spiral CT demonstrated 21 true positive cases, and seven true negative cases. There were four false negative cases and one false positive case. Sensitivity was 84%, specificity was 87%, diagnostic accuracy was 85%, positive predictive value was 95%, and negative predictive value was 64%. Evaluation of the esophagus with multidetector CT is a promising technique and easy to use, allowing panoramic exploration, virtual endoluminal visualization, accurate longitudinal and axial evaluations, and simultaneous evaluation of T and N parameters.

Esophageal Diseases↗
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Percutaneous image-guided radiofrequency ablation in the therapeutic management of hepatocellular carcinoma.

Owing to surveillance programs for detection of hepatocellular carcinoma (HCC) in patients with cirrhosis, more tumors are being detected at an early, asymptomatic stage. Percutaneous ablation is considered the best treatment option for patients with Child-Pugh class A or B cirrhosis and a single, nodular-type HCC smaller than 5 cm or as many as three HCC lesions, each smaller than 3 cm, when surgical resection or liver transplantation is not suitable. Radiofrequency ablation (RFA) has emerged as the most powerful method for percutaneous treatment of early-stage HCC. Recent studies have shown that RFA can achieve more effective local tumor control than ethanol injection and with fewer treatment sessions. In a randomized trial, local recurrence-free survival rates were significantly higher in patients who received RFA than in those treated by ethanol injection, and treatment allocation was confirmed as an independent prognostic factor by multivariate analysis. Due to advances in radiofrequency technology, RFA also has been used to treat patients with more advanced tumors. Preliminary reports have shown that RFA performed after balloon catheter occlusion of the hepatic artery, transarterial embolization, or chemoembolization results in increased volumes of coagulation necrosis, thus enabling successful destruction of large HCC lesions. This report reviews the current status of percutaneous, image-guided RFA in the therapeutic management of HCC.

Carcinoma, Hepatocellular↗
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CT colonography: contrast enhancement of benign and malignant colorectal lesions versus fecal residuals.

We retrospectively reviewed the computed tomographic colonographic datasets of 22 patients. Mean attenuation values of benign polyps before and after contrast administration were 30 +/- 15 HU and 90 +/- 18 HU, respectively. Mean attenuation values of colorectal cancer before and after contrast administration were 43 +/- 15 HU and 124 +/- 18 HU, respectively. The mean attenuation value of solid fecal residuals was 43 +/- 15 HU. The difference in attenuation value between precontrast and postcontrast studies of polyps was statistically significant (mean 60 HU, p < 0.01); the same was true for colorectal cancer (mean 81 HU, p < 0.01). The difference between postcontrast density of polyps and cancer with respect to density of solid fecal residuals was statistically significant (p < 0.01). The use of contrast medium could be of help in computed tomographic colonography for discriminating polypoid benign lesions and colorectal cancer from fecal residuals.

Colonic Polyps↗
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Endoluminal treatment of abdominal aortic aneurysms.

BACKGROUND: We report our preliminary results with endovascular treatment of abdominal aortic aneurysms (AAA). METHODS: Between October 1998 and June 2000, 64 patients (62 male, two female; mean age = 70 years) underwent endovascular repair of AAA. Different types of prostheses were used, both bifurcated (n = 58) and straight (n = 6). We performed duplex sonography and spiral computed tomographic angiography (CTA) at discharge and at 3, 6, 12, and 18 months. Follow-up ranged from 1 to 20 months. RESULTS: All procedures were successful, except for three immediate and one late surgical conversions (6.2%). One patient died 14 days after immediate surgical conversion. At discharge, CTA showed 13 endoleaks: three resolved spontaneously, six persisted during follow-up, and four (one angioplasty and three embolizations) were treated successfully. Stenosis of an iliac branch occurred in one patient after 3 months and was successfully treated by angioplasty. Late endoleaks were detected by imaging follow-up in four cases, three at 1 year and one at 6 months, requiring deployment of distal extender cuffs (n = 2), a proximal cuff (n = 1), and lumbar embolization (n = 2). CONCLUSION: Our preliminary experience supports the efficacy of endovascular repair in selected patients, but strict and accurate follow-up is required.

Aged↗
PubMedDate not supplied

Small hepatocellular carcinoma: differentiation from adenomatous hyperplasia with color Doppler US and dynamic Gd-DTPA-enhanced MR imaging.

BACKGROUND: To investigate the usefulness of color Doppler ultrasound (US) and dynamic Gd-DTPA-enhanced magnetic resonance (MR) imaging in the differentiation of small hepatocellular carcinoma (HCC) and adenomatous hyperplasia (AH). METHODS: Thirty-eight small (3 cm or less) nodular lesions (in 38 cirrhotic patients) with US features consistent with HCC underwent evaluation with color Doppler US and MR imaging. Breath-hold T1-weighted rapid acquisition spin echo MR sequence after bolus injection of 0.1 mmol/kg gadopentetate dimeglumine was used to evaluate dynamic enhancement. US-guided tissue-core percutaneous biopsy established the diagnosis: HCC in 28 cases and AH in 10. RESULTS: Color signals with pulsatile or continuous Doppler spectrum were demonstrated in 19 of 28 HCCs (68%) but in none of the AHs. Although there was considerable overlap in signal intensity between HCC and AH on both unenhanced T1- and T2-weighted images, early enhancement on breath-hold T1-weighted images obtained 40 s after starting contrast administration was observed in 22 of 28 HCCs (79%) but in none of the AHs. In 26 of 28 HCCs (93%), pulsatile or continuous flow at color Doppler US, early enhancement at dynamic MR imaging, or both were observed. CONCLUSION: Findings with color Doppler US and dynamic Gd-DTPA-enhanced MR imaging enable a reliable distinction between small HCC and AH.

Biopsy↗
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Intrahepatic metastatic nodules of hepatocellular carcinoma detected at lipiodol-CT: imaging-pathologic correlation.

BACKGROUND: The purpose of this study was to determine whether tiny (< 2 cm) areas of iodized-oil retention diagnosed as intrahepatic metastatic nodules of hepatocellular carcinoma (HCC) at computed tomography (CT) following intraarterial injection of Lipiodol (Lipiodol-CT) correlate with truly cancerous foci on the corresponding sectioned pathologic specimens. METHODS: Thirty-two consecutive patients with biopsy-proven HCC (26 men and six women, aged 41-72 years) underwent prospective evaluation with Lipiodol-CT before undergoing surgery (hepatic resection, 30 patients; liver transplantation, two patients). Imaging findings were correlated with intraoperative and pathologic findings. RESULTS: Twenty-one areas of retained Lipiodol (0.5-1.6 cm in diameter, mean +/- SD: 0.9 +/- 0.3 cm) had features consistent with intrahepatic metastatic nodules of HCC on Lipiodol-CT scans. Nineteen of the 21 areas correlated with tumor deposits at pathologic examination of the surgical specimens, whereas two of 21 were due to abnormal retention of iodized oil within noncancerous liver parenchyma. The positive predictive value of findings at Lipiodol-CT for the diagnosis of intrahepatic metastatic nodule of HCC was 90.5%. CONCLUSIONS: Findings at Lipiodol-CT enable a reliable diagnosis of intrahepatic metastatic nodules of HCC.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Fatal thrombosis of the portal vein following single-session percutaneous ethanol injection therapy of hepatocellular carcinoma.

Two weeks after percutaneous ethanol injection therapy for hepatocellular carcinoma, performed by injecting 110 mL ethanol in a single session with general anesthesia, a 69-year-old woman with well-compensated liver cirrhosis developed an extensive thrombosis of the whole portal tree that caused severe uncorrectable ascites and progressive deterioration of her general condition, resulting in death 6 weeks after the procedure.

Aged↗
PubMedDate not supplied

MR virtual endoscopy of the pancreaticobiliary tract: a feasible technique?

To evaluate the feasibility of magnetic resonance (MR) virtual endoscopy of the pancreaticobiliary tract by using MR cholangiopancreatography (MRCP) data sets as source images, we retrospectively reviewed MRCP data sets of 120 patients with Navigator software (GE/Medical Systems, Milwaukee, WI) that allowed display of inner views by surface rendering the internal wall of the bile ducts with simulated light and shadow.

Adolescent↗
PubMedDate not supplied

Spiral CT virtual endoscopy of abdominal arteries: clinical applications.

Virtual endoscopy enables the creation of endoluminal views of the aorta and its branches by processing spiral computed tomographic (CT) images, thereby allowing the preoperative and postoperative evaluations of abdominal aortic aneurysms, aneurysms of the splenic, celiac, and common iliac arteries, and renal artery stenoses. Moreover, it is helpful for verifying the position of stents and endoprostheses from within the aortic lumen. This method is a promising addition to spiral CT.

Aneurysm↗
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Signal suppression of normal liver tissue by phase corrected inversion recovery: a screening technique.

A new pulse sequence characterized by simultaneous multislice spin echo (SE) and short inversion time (TI) with inversion recovery (STIR) acquisitions is demonstrated. For the STIR component, a repetition time of 1,000 ms and TI of 210 ms were chosen to suppress the signal from normal liver at 0.5 T and create a fast sequence suitable for screening purposes. Phase correction of the STIR with the SE's signal as a reference resulted in high contrast real IR images that were free of phase error artifact. In 13 min the entire liver could be imaged in 14 adjacent slices, each slice portrayed in an ensemble of four images: a T1-weighted SE image, IR real and modulus images, and a T1 map. Forty-one patients with liver pathology and 10 normal volunteers were examined with the sequence implemented on a commercially available 0.5 T imager (Gyroscan; Phillips). Images demonstrated high liver-lesion contrast and sensitivity to liver lesions. Lesions of less than 1 cm in diameter and lymphomatous lesions, commonly occult to magnetic resonance, were detected.

Humans↗
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CT evaluation of chronic thromboembolic pulmonary hypertension.

Eight patients with chronic thromboembolic pulmonary hypertension (CTPH) that had been demonstrated by perfusion lung scan, pulmonary arteriography, and right heart catheterization had their pulmonary circulation evaluated by CT. Eight subjects without lung pathology were also studied for comparison. High resolution CT from apex to base with 1 cm thick sections after intravenous injection of contrast medium was performed in each individual. Emboli lodged in main pulmonary arteries on arteriography were regularly shown by CT, whereas those in segmental or smaller arteries were not detected. Diameters of the main pulmonary arteries measured on CT correlated with systolic pulmonary artery pressure (p < 0.001). The ratio between diameters of segmental arteries and the corresponding bronchi (A/B ratio) on CT was > 1 in 72 of 144 examined pulmonary segments (18 segments for each patient) in patients with CTPH. The ratio was > 1 in only 10 of 144 examined segments in normal control subjects. Dilatation of bronchial arteries was present in four of eight patients with CTPH. The parenchymal density in patients with CTPH was significantly higher in the axial than in the middle or peripheral lung compartments. In conclusion, CT may help with the diagnosis of CTPH by detecting thrombi of main arteries and by showing characteristic findings; moreover, it is accurate in estimating pulmonary arterial pressure secondary to thromboembolic obstruction.

Angiography↗
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Response of hepatocellular carcinoma to percutaneous ethanol injection: CT and MR evaluation.

OBJECTIVE: The aim of the present study was to perform a comparative assessment of the contribution of imaging examinations to the evaluation of the response of hepatocellular carcinoma (HCC) to percutaneous ethanol injection (PEI). MATERIALS AND METHODS: Twenty-five small HCCs (< 5 cm in diameter) were treated by means of PEI. The outcome of treatment, established on the basis of percutaneous biopsy and a 10 to 26 month follow-up, was complete necrosis in 23 of 25 cases and tumor persistence in 2 of 25. RESULTS: While ultrasound proved to be unable to distinguish posttreatment fibrosis from persisting neoplastic tissue, contrast-enhanced CT correctly identified the two cases of treatment failure, which showed the presence of enhancing areas within the lesion. The remaining 23 cases displayed a hypodense appearance, with no contrast enhancement on CT. Magnetic resonance demonstrated ethanol-induced coagulative necrosis as marked hypointensity on T2-weighted images in 21 of 25 cases. In four cases areas of high signal intensity on T2-weighted images within the nodule were observed after PEI: In two cases they were associated with tumor persistence, and in the other two with the presence of liquefactive necrosis. CONCLUSION: Our results demonstrate that different necrotic phenomena following ethanol injection therapy of HCCs may result in variable MR appearance. Although the location of hyperintense areas may suggest a differential diagnosis (central hyperintensity being more likely due to necrosis), CT remains the more reliable technique in the assessment of the response of HCC to PEI.

Aged↗
PubMedDate not supplied

Contrast-enhanced time-resolved MR angiography of spinal vascular malformations.

PURPOSE: The purpose of this work was to assess the potential and limitations of a contrast-enhanced time-resolved MR angiography technique for evaluation of spinal vascular malformations. METHOD: Two patients with intramedullary arteriovenous (AV) malformations and three patients with dural AV fistula underwent four serial acquisitions, every 17-20 s, of 20-32 coronal 1.5- to 2-mm-thick partitions with a fast 3D SPGR sequence after injection of 0.2-0.3 mmol/kg paramagnetic contrast agent. This was followed by coronal 3D and sagittal or coronal 2D phase contrast (PC) MR angiography. RESULTS: No spinal vessels were visualized in the first (baseline) series. In patients with intramedullary AV malformations, the arterial feeders, nidus, and perimedullary draining veins were visualized in the second (early) series. In the third (intermediate) series, the arterial feeder vanished, whereas the intercostal and lumbar veins appeared. In patients with dural AV fistula, abnormal intraspinal vessel appeared in the third series and persisted, although less conspicuous, in the fourth (late) series. Contrast-enhanced time-resolved MR angiography demonstrated the venous components of the lesion with better conspicuity than 3D PC MR angiography, whereas it was inferior for visualization of arterial feeders. Moreover, indirect identification of the level of the dural AV fistula was possible only on the phase display of the 2D PC MR angiography. CONCLUSION: Contrast-enhanced time-resolved MR angiography is a useful complement to PC MR angiography for the evaluation of spinal vascular malformation.

Arteriovenous Fistula↗